This invention relates to an electrically actuated overhead garage door opener with solenoid actuated latches of the type disclosed in my U.S. Pat. No. 4,254,582.
Automatic garage door openers have now become well established as convenient additions to residences (houses, condominiums and apartments). In addition to the convenience of allowing one to open their garage door by a radio actuated switch, they provide a degree of security for the person and the home, since a garage door controlled by such a system can only be opened from the outside by a coded ratio signal or a key inserted in a lock in the wall adjacent to the door.
As noted in my earlier patent, overhead garage doors are pivotally mounted to move from a closed position upwardly and rearwardly in one flat piece to a nearly horizontal position overhead. For closing, the door is moved pivotally to an upright, nearly vertical position. While an electrical garage door opener attached at the center will hold it in the upright position secure against it being pivotally moved upwardly and rearwardly by an unauthorized person, it may be possible to pry open a corner of the door, particularly of a double car garage, sufficiently to allow a small person to wriggle into the garage. Once in the garage, the person will have access to a pushbutton to open the door, unless the pushbutton is inside the house. But even then, the person may be skillful enough to short leads in the garage door opener to simulate actuation of the pushbutton, or unfasten the garage door from the opener and manually open it.
When the garage is attached to the house or condominium, as is most often the case where electrical garage door openers are used. The person having gained access to the garage with its door closed may then gain access to the home unobserved from the outside. Then after burglarizing the home, the person may open the garage door for a fast exit even though burdened by the possessions being taken. In either the case of an attached or an unattached garage, it would be desirable to provide solenoid actuated latches in the lower corners of the garage doors to prevent a person from wriggling in through a pryed corner.
My earlier patent discloses solenoid actuated latches connected in series with the motor for the garage door opener. When the garage door is to be opened or closed, the electrical door opener provides current at 120 volts ac to the motor. By connecting the coils of the solenoid latches in series with the motor, the solenoid armature is pulled in along the axis of the coil to unlatch the corners of the door whenever the motor of the door opener is running. However, in that arrangement, the coils are necessarily large and expensive. There is also the need of having to wire the latches for 120 volts, and the fact that the high voltage coils consume a significant amount of power. It would be preferable to actuate the solenoids from the door opener with a lower voltage, such as 24 volts.
In order to reduce the power used by the solenoid latches, the initial current used to pull the armatures in should be reduced to just that current necessary to hold them in. Once the garage door reaches its limits, power to the motor is shut off, and the solenoids are de-energized, causing their spring-loaded armatures to pop out and latch the corners of the door in the upright (closed) position. My copending application, Ser. No. 06/587,358, filed Mar. 8, 1984, titled GARAGE DOOR LOCK SYSTEM, discloses a preferred solenoid latch assembly comprised of a box secured to the garage door frame. The latch solenoid is mounted in the box which has two parallel walls with aligned holes through which the solenoid armature or locking pin passes when its coil is not energized. A latch plate mounted on the garage door fits between the parallel walls of the solenoid box with a hole aligned with the holes in the walls of the box to receive the locking pin. The disclosure of that application, as well as my prior patent are incorporated herein by reference.
It is important that the solenoid latches be energized in time to pull the armature locking pins in before the door opener motor has moved the door by any significant amount. Otherwise, the armature locking pins may become jammed between the door plate and the walls of the solenoid box, in which case the garage door will not open, the limit switches of the door opener are not actuated to turn the motor off, and the motor may be damaged before a circuit breaker opens. It is therefore desirable to have a high initial drive current to the solenoid coils once the radio receiver (or pushbutton) switch has been closed, to apply drive current to the motor of the door opener. Thereafter, the solenoid latch current may be reduced to hold the lach armatures in until power has been removed from the motor by the door opener, at which time the de-energized solenoid releases the locking pins to latch the corners of the door.
The system of my earlier patent was designed to be integrated into a garage door opener, at least to the extent that it obtains its operating current from the same current supplied to the automatic garage door opener. The need exists for such a garage door lock system that is powered independently of the electrical garage door opener, and yet is responsive to the garage door opener's operation to appropriately unlatch and latch the lock mechanisms so as to not interfere with the normal operation of the automatic garage door opener, or require disassembly and/or modification of the door opener.
The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention will best be understood from the following description when read in connection with the accompanying drawings.